A tap aerator with a jet divider which is realized as a diffusor which interacts with a diffusor ring is already previously known from DE 10 2010 048 701 A1.
In the case of said previously known tap aerator, it is provided that the diffusor ring encompasses the diffusor at least in regions on the outside and secures it axially as a result, which allows for a space-saving arrangement in the axial direction and above all produces centering of the diffusor. However, said arrangement requires a relatively large amount of space in the radial direction because the diffusor ring encompasses the ring-shaped holding region of the diffusor on the outside and consequently protrudes in the radial direction.
U.S. Pat. No. 5,242,119 A has already made known a tap aerator with a mounting housing which is mountable on the water outlet of a sanitary outlet fitting by means of a fastening ring which is realized as a sleeve-shaped outlet mouth piece. So that the previously known tap aerator can form a homogeneous and non-spraying water jet, a jet divider, which has to break down inflowing water into a plurality of individual jets, is inserted in its mounting housing. The jet divider is realized for this purpose as a perforated plate which comprises a multitude of throughflow holes which are arranged with respect to one another along a circle. A further perforated plate, which has elongated holes which are oriented in the circumferential direction, and which is separated from the perforated plate serving as a jet divider by means of a metal sieve, is arranged in the direction of flow behind the perforated plate which serves as a jet divider. The two perforated plates and the metal sieve separating them rest on a ring flange which is integrally molded on the inside circumference of a sleeve-shaped housing part. Said inflow-side housing part is inserted into an outflow-side housing part of the mounting housing until a holding region, which is integrally molded on the outer circumference of the inflow-side housing part and serves as a holding ring, rests on the inflow-side end edge of the outflow-side housing part.
U.S. Pat. No. 4,403,739 A has already made known a tap aerator, the mounting housing of which is fastenable on the water outlet of a sanitary outlet fitting by means of a fastening ring. An insert part, which is realized as a jet divider and has to divide and break apart the inflowing water jet into a plurality of individual jets, is insertable into the mounting housing of the previously known tap aerator. The jet divider has a perforated plate which comprises a plurality of throughflow holes which are arranged with respect to one another along a perforated circle. The first perforated plate is placed into an indentation, adapted in shape, of a second perforated plate which also comprises a plurality of throughflow holes which are in alignment with the throughflow holes of the first perforated plate when the two perforated plates are in a relative position, whilst in another relative position said holes only overlap in part and expose a reduced throughflow region. It is true that a holding region which acts as a holding ring can be seen on the second perforated plate—but there is absolutely no component which serves as a diffusor which also has such a holding region which acts as a holding ring, and neither is there a ring-shaped diffusor ring.
EP 0 631 020 A1 has previously made known a tap aerator with a mounting housing which is mountable on the water outlet of a sanitary outlet fitting by means of a fastening ring. Several metal sieves, which are slightly spaced apart from one another and from which the outflow-side metal sieve forms the outlet end face of the tap aerator, are placed into the mounting housing. A perforated plate that serves as a jet divider is placed into the mounting housing on the inflow-side of the metal sieve. The perforated plate that serves as a jet divider does comprise a ring-shaped holding region which acts as a holding ring and is arranged at the edge—beyond the mounting housing and the perforated plate that serves as a jet divider there is, however, no component to be seen that could serve as a ring-shaped diffusor ring with a holding region arranged at the edge.
Consequently, the object is to create a tap aerator of the type defined in the introduction where the diffusor and the diffusor ring are able to interact in the manner known from DE 10 2010 048 701 A1, nevertheless however, for the diffusor ring in the radial direction only as small as possible a radial dimension being required, wherein the diffusor and the diffusor ring are to be secured in the most simple manner in the mounting housing of the tap aerator.